1. Field of the Invention
The present invention relates to a transmission system for an automotive vehicle suitable for a power transmission between a drive (or power) source such as an internal combustion engine and a transmission such as an automatic transmission.
2. Description of the Related Art
In general, in an automotive vehicle equipped with the automatic transmission, a fluid coupling device such as a torque converter has been used as the transmission system. Such a torque converter as described above is exemplified by a Japanese Technical Book titled as an automotive engineering (published by Kabushiki Kaisha Sankaido on Nov. 20, 1980).
A clutch is well known as another transmission system.
An automatic clutch system has been proposed which automatically engages or disengages its clutch according to its necessity in view of a demand for operation easiness.
The automatic clutch in which a dry-type, single-plate clutch has been used.
However, a power loss occurs in the torque converter due to an implementation of a power transmission via a fluid and a fuel consumption accordingly becomes worsened. On the other hand, the power loss in the case of the clutch type transmission system is not easy to occur but it is difficult to perform a low-speed-and-high-torque transmission which is a merit of the torque converter.
It is an object of the present invention to provide a transmission system for an automotive vehicle which is superior to a torque transmission efficiency with less fuel consumption than that the torque converter has.
The above-described object can also be achieved by providing a method applicable to a transmission system for an automotive vehicle, comprising: interposing a planetary gear between a drive axle in which a torque is transmitted from a power source of the vehicle and an output axle via which the transmitted torque is outputted, the planetary gear comprising a ring gear fixed to a housing: interposing a first clutch between a carrier of the planetary gear and the drive axle; interposing a second clutch between the carrier of the planetary gear and the output axle; and interposing a third clutch between a sun gear of the planetary gear and the drive axle.
The above-described object can also be achieved by providing a method applicable to a transmission system for an automotive vehicle, comprising: interposing a planetary gear between a drive axle in which a torque is transmitted from a power source of the vehicle and an output axle via which the transmitted torque is outputted, the planetary gear comprising a ring gear fixed to a housing: interposing a first clutch between a carrier of the planetary gear and the drive axle; interposing a second clutch between the carrier of the planetary gear and the output axle; and interposing a second clutch between a sun gear of the planetary gear and the drive axle.
The other objects and features of this invention will become understood from the following description with reference to the accompanying drawings.